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I'm getting "Duplicate name of actual target" error. What
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<div class="titlepage"><div><div><h2 class="title">
<a name="bbv2.faq"></a>Chapter8.Frequently Asked Questions</h2></div></div></div>
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<dt><span class="section"><a href="faq.html#id2599088">
How do I get the current value of feature in Jamfile?
</a></span></dt>
<dt><span class="section"><a href="faq/s02.html">
I'm getting "Duplicate name of actual target" error. What
does it mean?
</a></span></dt>
<dt><span class="section"><a href="faq/envar.html">
Accessing environment variables
</a></span></dt>
<dt><span class="section"><a href="faq/s04.html">
How to control properties order?
</a></span></dt>
<dt><span class="section"><a href="faq/s05.html">
How to control the library order on Unix?
</a></span></dt>
<dt><span class="section"><a href="faq/external.html">Can I get output of external program as a variable in a Jamfile?
</a></span></dt>
<dt><span class="section"><a href="faq/s07.html">How to get the project-root location?
</a></span></dt>
<dt><span class="section"><a href="faq/s08.html">How to change compilation flags for one file?
</a></span></dt>
<dt><span class="section"><a href="faq/dll-path.html">Why are the <code class="computeroutput">dll-path</code> and
<code class="computeroutput">hardcode-dll-paths</code> properties useful?
</a></span></dt>
<dt><span class="section"><a href="recipies/site-config.html">Targets in site-config.jam</a></span></dt>
<dt><span class="section"><a href="faq/header-only-libraries.html">Header-only libraries</a></span></dt>
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<div class="titlepage"><div><div><h2 class="title" style="clear: both">
<a name="id2599088"></a>
How do I get the current value of feature in Jamfile?
</h2></div></div></div>
<p>
This is not possible, since Jamfile does not have "current" value of any
feature, be it toolset, build variant or anything else. For a single invocation of
<code class="filename">bjam</code>, any given main target can be built with several property sets.
For example, user can request two build variants on the command line. Or one library
is built as shared when used from one application, and as static when used from another.
Obviously, Jamfile is read only once, so generally, there's no single value of a feature
you can access in Jamfile.
</p>
<p>A feature has a specific value only when building a target, and there are two ways how you
can use that value:</p>
<div class="itemizedlist"><ul type="disc">
<li>Use conditional requirements or indirect conditional requirements. See
<a href="advanced/targets.html#bbv2.advanced.targets.requirements.conditional">the section called “Requirements”</a>.</li>
<li>Define a custom generator and a custom main target type. The custom generator can do arbitrary processing
or properties. See the <a href="extender.html" title="Chapter6.Extender Manual">Chapter6, <i>Extender Manual</i></a>.
</li>
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